The iPhone XS and XS Max will be available to preorder starting Friday before going on sale a week later, on September 21. The iPhone XR won’t be available until October 26, with preorders opening up one week before that.

Still, if you’re considering any of the fancy new iPhones from Apple but already own an iPhone, you should wait until iOS 12 becomes available, on Monday, before making a final decision.

iOS 12 brings a ton of improvements to the iPhone, but the biggest changes will come in the form of speed and performance – even on older devices.

Apple says apps will launch up to 40 percent faster on the iPhone 6S, for instance, and you’ll be able to open the camera up to 70 percent faster.

App developers and early adopters already running the beta version of iOS 12 have reported great improvements on older devices.

Holding onto your device is a good thing, generally speaking. Of course, owning the new, shiny gadget is always fun and exciting, but getting more mileage from your current iOS device means you’re saving yourself money and helping the environment.

As Apple’s Lisa Jackson said of iPhones at Wednesday’s event, “because they last longer, you can keep using them – and keeping using them is the best thing for the planet.”

So perhaps don’t rush into the new iPhones right away. Try iOS 12 first, and see if you feel the same way afterward.